Several types of devices have been proposed for protecting vehicle occupants during a crash event. Such devices can be categorized as being either passive devices or active devices.
Passive safety devices deform to absorb energy during a crash event. Passive devices, however, remain in a fixed position during a crash event. Accordingly, there may be a relatively large distance over which the vehicle occupant may accelerate during a crash event before encountering a passive device.
Active safety devices are those that deploy during a crash event so that they are positioned relatively close to the vehicle occupants to cushion them. By reducing the distance between the occupant and the safety device, the occupant has less time to accelerate before encountering the safety device, and more time to decelerate on engaging the safety device, and therefore is less likely to sustain injury. A typical active safety device incorporates an air bag that inflates immediately after a crash event. The air bag is typically a fabric bag that is folded and held in a housing until it is deployed. Air bag devices, however, add complexity and cost to the vehicular subassemblies to which they are added.
It would be advantageous to provide an active safety device that is relatively inexpensive to incorporate into a vehicle.
It would also be advantageous to provide an active safety device that is relatively easy to service.